Cervicomedullary Compression in Achondroplasia: A Feared Complication and an Unforeseen Risk Factor of Posterior Circulation Stroke.

Achondroplasia is an autosomal dominant disorder with defect in the ossification of the cartilage of long bones. Many bony abnormalities constitute its clinical features, with craniovertebral junction (CVJ) anomalies being one of most common issues which need to be addressed at the earliest. CVJ anomalies in individuals may cause neurovascular compression, which may warrant an early surgery to prevent catastrophic complications. Posterior circulation strokes secondary to CVJ anomalies are well known. We hereby present an unusual case of posterior circulation stroke in an achondroplastic dwarf who presented to our tertiary care centre. Prospective case study. The present case adds to the existing literature about one of the preventable causes of fatal posterior circulation strokes in the young. A high index of suspicion for neurovascular compression at the foramen magnum and early initiation of treatment in achondroplastic young individuals may have gratifying results.

Management of complete intra-articular distal femur and patellar fractures in an achondroplastic young adult; small is challenging' revisited: a case-report.

BACKGROUND: People with achondroplasia exhibit distinct physical characteristics, but their cognitive abilities remain within the normal range. The challenges encountered during surgical procedures and perioperative care for achondroplastic individuals, are underrepresented in the existing literature. CASE PRESENTATION: In this report, the management of a 26-year-old North-African achondroplastic male is highlighted. The patient suffered a complete intra-articular distal femur fracture (AO/OTA 33-C1) and an ipsilateral patella fracture (AO/OTA 34-C1). The patient's unusual anatomical variations and the lack of suitable orthopedic implants posed significant surgical challenges, particularly in the context of a resource-limited developing country. Facial and spinal deformities, which are common in patients with achondroplasia, further complicated the anesthetic approach. CONCLUSIONS: The limited information on operative management of fractures in achondroplastic patients necessitated independent decision-making and diverging from the convenient approach where clear guidance is available in the literature.

Surgical outcome after treatment of thoracolumbar spinal stenosis in adults with achondroplasia.

PURPOSE: To describe the complications and the outcome of patients with achondroplasia undergoing thoracolumbar spinal surgery. METHODS: Retrospective analysis of prospectively collected data of all patients with achondroplasia undergoing surgery within the years 1992-2021 at the thoracic and/or lumbar spine. The outcome was measured by analyzing the surgical complications and revisions. The patient-rated outcome was assessed with the COMI score from 2005 onwards. RESULTS: A total of 15 patients were included in this study undergoing a total of 31 surgeries at 79 thoracolumbar levels. 12/31 surgeries had intraoperative complications consisting of 11 dural tears and one excessive intraoperative bleeding. 4/18 revision surgeries were conducted due to post-decompression hyperkyphosis. The COMI score decreased from 7.5 IQR 1.4 (range 7.1-9.8) preoperatively to 5.3 IQR 4.1 (2.5-7.5) after 2 years (p = 0.046). CONCLUSION: Patients with achondroplasia, the most common skeletal dysplasia condition with short-limb dwarfism, are burdened with a congenitally narrow spinal canal and are commonly in need of spinal surgery. However, surgery in these patients is often associated with complications, namely dural tears and post-decompression kyphosis. Despite these complications, patients benefit from surgical treatment at a follow-up of 2 years after surgery.

Evaluation of functionality-mobility in patients with skeletal dysplasias. Application of the STEMS tool ("everyday symptoms and mobility screening tool for skeletal dysplasias").

Individuals with differing forms of skeletal dysplasias (SD) frequently report impaired mobility and symptoms. With the objetive to evaluate mobility and associated symptoms in people with SD at an Argentinian pediatric hospital, using an Argentinian version of the Screening Tool for Everyday Mobility and Symptoms (STEMS), a simple questionnaire that allows clinicians to quickly identify the presence of symptoms associated with mobility in people with SD, while considering different environmental settings and the use of assistive devices, an analytical study of a consecutive sample of patients older than 5 years with SD and their affected relatives was carried out.Diagnosis, comorbidities, socioenvironmental, therapeutic, auxological and mobility variables were recorded. The presence and intensity of symptoms was noted through use of both the STEMS and validated scales. Descriptive, association and correlation analyzes were performed. One hundred and nineteen individuals with SD were enrolled in the study and divided into groups: Osteogenesis Imperfecta (OI, n = 55), Achondroplasia (ACH, n = 36) and Other SD resulting in disproportionate short stature (n = 28). Mobility assistive devices were almost exclusively used by individuals with OI. They were more frequently used by individuals with overweight and obesity, more severe form of the disease and in the outdoor settings. Two thirds (66.4%) of the individuals assessed in this study reported pain, 87.4% reported fatigue, and 58.8% reported both pain and fatigue. The intensity of symptoms was similar between groups and correlated with age and auxological variables. The STEMS was clear, easy and quick to use for identifying presence of pain and fatigue in this population group. The STEMS proved to be a simple and useful tool for evaluating functional mobility and associated symptoms in our population of individuals with SD.

Evaluation of simultaneous bilateral femoral distraction osteogenesis with antegrade intramedullary lengthening nails in achondroplasia with rhizomelic short stature: a retrospective study of 15 patients with a minimum follow-up of 2 years.

BACKGROUND AND PURPOSE: Bilateral femoral distraction osteogenesis in patients with achondroplasia is insufficiently reported. We aimed to perform the first study that exclusively analyzed simultaneous bilateral femoral distraction osteogenesis with motorized intramedullary lengthening nails via an antegrade approach in patients with achondroplasia focused on reliability, accuracy, precision, and the evolving complications. PATIENTS AND METHODS: In this retrospective singlecenter study we analyzed patients with achondroplasia who underwent simultaneous bilateral femoral lengthening with antegrade intramedullary lengthening nails between October 2014 and April 2019. 15 patients (30 femoral segments) of median age 14 years (interquartile range [IQR] 12-15) were available for analysis. The median follow-up was 29 months (IQR 27-37) after nail implantation. RESULTS: The median distraction length per segment was 49 mm (IQR 47-51) with a median distraction index of 1.0 mm/day (IQR 0.9-1.0), and a median consolidation index of 20 days/cm (IQR 17-23). Reliability of the lengthening nails was 97% and their calculated accuracy and precision were 96% and 95%, respectively. The most common complication was temporary restriction of knee range of motion during distraction in 10 of 30 of the lengthened segments. 1 patient was treated with 2 unplanned additional surgeries due to premature consolidation. CONCLUSION: The method is reliable and accurate with few complications.

Alteration of major venous drainage routes in a patient with achondroplasia after ventriculoperitoneal shunt placement.

Achondroplasia is the most common form of dwarfism, caused by a mutation in fibroblast growth factor receptor 3 gene, leading to multiple pathological conditions. Herein, we present a case of an infant with achondroplasia associated with hydrocephalus and severe foramen magnum stenosis. Computed tomography (CT) venography showed prominent suboccipital emissary veins comprising major venous drainage routes and hypoplastic transverse sinuses, which increased the risk of foramen magnum decompression. The infant was initially treated with ventriculo-peritoneal (VP) shunt. After 8 months, CT venography showed regression of suboccipital emissary veins and more prominent transverse sinuses. Subsequently, foramen magnum decompression was safely performed without sacrificing major venous drainage routes.

Prophylactic Intramedullary Rodding After Femoral Lengthening in Patients With Achondroplasia and Hypochondroplasia.

BACKGROUND: Femoral fracture after femoral lengthening in patients with achondroplasia and hypochondroplasia is a frequent complication, occurring in up to 30%. The purpose of this study is to demonstrate the effectiveness of prophylactic intramedullary rodding in preventing this complication. METHODS: Multicenter retrospective study involving 86 femoral lengthening procedures in 43 patients with achondroplasia or hypochondroplasia. Forty-two femora (21 patients) were prophylactically managed with intramedullary Rush rodding after external fixation removal (11 females and 10 males, mean age 14.6 years) compared with 44 femora (22 patients) without prophylactic intramedullary rodding (13 females and 9 males, mean age 15.2 years). The mean amount of lengthening in the rodding group was 13.3 cm (52.6%) with an External Fixation Index of 25.8 days/cm; in patients without rodding was 14.3 cm (61.5%) and 24.5 days/cm, respectively. RESULTS: Seven cases (15.9%) without rodding developed fractures. Four of them required surgical correction due to displacement or shortening. Only 1 patient (2.4%) had fracture of the femur after prophylactic rodding, and surgery was not required. The incidence of femur fracture was significantly lower in the prophylactic rodding group compared with the nonrodding group (2.4% vs. 15.9%, respectively; P =0.034). There were no cases of infection or avascular necrosis. CONCLUSIONS: Prophylactic intramedullary rodding is a safe and effective method for preventing femoral fractures after femoral lengthening in patients with achondroplasia or hypochondroplasia. LEVEL OF EVIDENCE: Level III-a retrospective comparative study.

Achondroplasia Natural History Study (CLARITY): 60-year experience with hydrocephalus in achondroplasia from four skeletal dysplasia centers.

OBJECTIVE: The objective of this study was to describe the incidence and management of hydrocephalus in patients with achondroplasia over a 60-year period at four skeletal dysplasia centers. METHODS: The Achondroplasia Natural History Study (CLARITY) is a registry for clinical data from achondroplasia patients receiving treatment at four skeletal dysplasia centers in the US from 1957 to 2017. Data were entered and stored in a REDCap database and included surgeries with indications and complications, medical diagnoses, and radiographic information. RESULTS: A total of 1374 patients with achondroplasia were included in this study. Of these, 123 (9%) patients underwent treatment of hydrocephalus at a median age of 14.4 months. There was considerable variation in the percentage of patients treated for hydrocephalus by center and decade of birth, ranging from 0% to 28%, although in the most recent decade, all centers treated less than 6% of their patients, with an average of 2.9% across all centers. Undergoing a cervicomedullary decompression (CMD) was a strong predictor for treatment of hydrocephalus (OR 5.8, 95% CI 3.9-8.4), although that association has disappeared in those born since 2010 (OR 1.1, 95% CI 0.2-5.7). In patients born since 1990, treatment of hydrocephalus with endoscopic third ventriculostomy (ETV) has become more common; it was used as the first line of treatment in 38% of patients in the most recent decade. Kaplan-Meier analysis suggests that a single ETV will treat hydrocephalus in roughly half of these patients. CONCLUSIONS: While many children with achondroplasia have features of hydrocephalus with enlarged intracranial CSF spaces and relative macrocephaly, treatment of hydrocephalus in achondroplasia patients has become relatively uncommon in the last 20 years. Historically, there was a significant association between symptomatic foramen magnum stenosis and treatment of hydrocephalus, although concurrent treatment of both has fallen out of favor with the recognition that CMD alone will treat hydrocephalus in some patients. Despite good experimental data demonstrating that hydrocephalus in achondroplasia is best understood as communicating in nature, ETV appears to be reasonably successful in certain patients and should be considered an option in selected patients.

How pain affect real life of children and adults with achondroplasia: A systematic review.

The clinical features of achondroplasia can cause acute self-limited pain that can evolve into chronic pain. Pain causes a low quality of life, in terms of physical, emotional, social, and school functioning in both adult and children with achondroplasia. We conducted a systematic review according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement to describe prevalence, assessment tools, causes and management strategies of pain in this rare disease. We found that shoulder and knee pain is typically referred during infancy, while knee pain is generally referred around 5-6 years of age. The prevalence of general pain in adolescence can be as high as 90%. Chronic pain in the achondroplasia population increases with age, with up to 70% of adults reporting general pain and back pain. Recognizing the multiple determinants of acute and chronic pain in patients with achondroplasia may enable physicians to better understand and manage this burden, particularly with the advent of new drugs that may modify some of the striking features of achondroplasia.

Neurosurgical management of cervicomedullary compression, spinal stenosis, and hydrocephalus in pediatric achondroplasia: a systematic review.

OBJECTIVE: Pediatric achondroplasia is often associated with conditions requiring neurosurgical intervention, including CSF diversion and multilevel spinal decompression. However, there is a lack of clinical guidelines and reliable estimates of the benefits and risks of these interventions. This study aimed to summarize the literature on the neurosurgical management of pediatric achondroplasia patients in order to aid in determining optimal treatment and standardization of care. METHODS: A systematic review of peer-reviewed studies with an objective diagnosis of achondroplasia, patient demographic information, and available data on neurosurgical interventions performed before 18 years of age for cervicomedullary compression, spinal stenosis, and hydrocephalus was performed. Study quality and risks of bias were assessed using standardized scores. Independent patient data on surgical indications, outcomes, reoperations, and complication risks were aggregated using means and percentages. RESULTS: Of 204 records, 25 studies with 287 pediatric achondroplasia patients (mean age 25 ± 36 months) treated for cervicomedullary compression (n = 153), spinal stenosis (n = 100), and obstructive hydrocephalus (n = 34) were evaluated. Symptomatic cervicomedullary compression occurred early in life (mean age 31 ± 25 months), with apnea (48%), T2-weighted MRI cord signal (28%), myelopathy (27%), and delayed motor skills (15%) requiring foramen magnum decompression observed in 99% of patients, as well as cervical laminectomy in 65% of patients. Although 91% of treated patients had resolution of symptoms, 2% mortality, 9% reoperation, and 21% complication rates were reported. Spinal stenosis was treated in relatively older children (mean age 13 ± 3 years) with laminectomy (23%), as well as with instrumented fusion (73%) for neurogenic claudication (59%), back pain (15%), and sciatica (8%). Although 95% of patients had symptom resolution after surgery, 17% reported complications and 18% required reoperation. Of the hydrocephalus patients (mean age 56 ± 103 months), half were treated with endoscopic third ventriculostomy (ETV) and half had a shunt placed for progressive ventriculomegaly (66%), headaches (32%), and delayed cognitive development (4%). The shunted patients had a 3% mortality rate and an average of 1.5 shunt revisions per patient. None of the patients who underwent ETV as the primary procedure required a revision. CONCLUSIONS: Neurosurgical intervention for pediatric achondroplasia conditions, including cervicomedullary compression, spinal stenosis, and hydrocephalus, is associated with high recovery rates and good outcomes. However, complications and reoperations are common. Further studies with follow-up into adulthood are needed to evaluate the long-term outcomes.

European Achondroplasia Forum guiding principles for the detection and management of foramen magnum stenosis.

Foramen magnum stenosis is a serious, and potentially life-threatening complication of achondroplasia. The foramen magnum is smaller in infants with achondroplasia, compared with the general population, and both restricted growth in the first 2 years and premature closure of skull plate synchondroses can contribute to narrowing. Narrowing of the foramen magnum can lead to compression of the brainstem and spinal cord, and result in sleep apnoea and sudden death. There is a lack of clarity in the literature on the timing of regular monitoring for foramen magnum stenosis, which assessments should be carried out and when regular screening should be ceased. The European Achondroplasia Forum (EAF) is a group of clinicians and patient advocates, representative of the achondroplasia community. Members of the EAF Steering Committee were invited to submit suggestions for guiding principles for the detection and management of foramen magnum stenosis, which were collated and discussed at an open workshop. Each principle was scrutinised for content and wording, and anonymous voting held to pass the principle and vote on the level of agreement. A total of six guiding principles were developed which incorporate routine clinical monitoring of infants and young children, timing of routine MRI screening, referral of suspected foramen magnum stenosis to a neurosurgeon, the combination of assessments to inform the decision to decompress the foramen magnum, joint decision making to proceed with decompression, and management of older children in whom previously undetected foramen magnum stenosis is identified. All principles achieved the ≥ 75% majority needed to pass (range 89-100%), with high levels of agreement (range 7.6-8.9). By developing guiding principles for the detection and management of foramen magnum stenosis, the EAF aim to enable infants and young children to receive optimal monitoring for this potentially life-threatening complication.

Achondroplasia natural history study (CLARITY): 60-year experience in orthopedic surgery from four skeletal dysplasia centers.

BACKGROUND: The purpose of this study was to describe the frequency and risk factors for orthopedic surgery in patients with achondroplasia. CLARITY (The Achondroplasia Natural History Study) includes clinical data from achondroplasia patients receiving treatment at four skeletal dysplasia centers in the United States from 1957 to 2018. Data were entered and stored in a Research Electronic Data Capture (REDCap) database. RESULTS: Information from one thousand three hundred and seventy-four patients with achondroplasia were included in this study. Four hundred and eight (29.7%) patients had at least one orthopedic surgery during their lifetime and 299 (21.8%) patients underwent multiple procedures. 12.7% (n = 175) of patients underwent spine surgery at a mean age at first surgery of 22.4 ± 15.3 years old. The median age was 16.7 years old (0.1-67.4). 21.2% (n = 291) of patients underwent lower extremity surgery at a mean age at first surgery of 9.9 ± 8.3 years old with a median age of 8.2 years (0.2-57.8). The most common spinal procedure was decompression (152 patients underwent 271 laminectomy procedures), while the most common lower extremity procedure was osteotomy (200 patients underwent 434 procedures). Fifty-eight (4.2%) patients had both a spine and lower extremity surgery. Specific risk factors increasing the likelihood of orthopedic surgery included: patients with hydrocephalus requiring shunt placement having higher odds of undergoing spine surgery (OR 1.97, 95% CI 1.14-3.26); patients having a cervicomedullary decompression also had higher odds of undergoing spine surgery (OR 1.85, 95% CI 1.30-2.63); and having lower extremity surgery increased the odds of spine surgery (OR 2.05, 95% CI 1.45-2.90). CONCLUSIONS: Orthopedic surgery was a common occurrence in achondroplasia with 29.7% of patients undergoing at least one orthopedic procedure. Spine surgery (12.7%) was less common and occurred at a later age than lower extremity surgery (21.2%). Cervicomedullary decompression and hydrocephalus with shunt placement were associated with an increased risk for spine surgery. The results from CLARITY, the largest natural history study of achondroplasia, should aid clinicians in counseling patients and families about orthopedic surgery.

Unravelling the pathogenesis of foramen magnum stenosis in patients with severe achondroplasia: a CT-based comparison with age-matched controls and FGFR3 craniosynostosis syndromes.

OBJECTIVE: Foramen magnum(FM) stenosis can be responsible for acute and chronic damage to the cervicomedullary junction in children with achondroplasia. The bony anatomy and patterns of suture fusion of the FM in this context are incompletely understood, yet becoming increasingly important in the light of novel medical therapies for achondroplasia. The objective of this study was to describe and quantify bony anatomy and fusion patterns of FM stenosis in patients with achondroplasia using CT scans, comparing them to age-matched controls and other FGFR3 craniosynostosis patients. METHODS: Patients with achondroplasia and severe FM stenosis, classified as achondroplasia foramen magnum score(AFMS) grades 3 and 4, were identified from a departmental operative database. All had pre-operative CT scans of the craniocervical junction. Measurements obtained comprised sagittal diameter (SD), transverse diameter (TD), foramen magnum area, and opisthion thickness. Anterior and posterior interoccipital synchondroses (AIOS and PIOS) were graded by the extent of fusion. These measurements were then compared with CT scans from 3 age-matched groups: the normal control group, children with Muenke syndrome, and children with Crouzon syndrome with acanthosis nigricans (CSAN). RESULTS: CT scans were reviewed in 23 cases of patients with achondroplasia, 23 normal controls, 20 Muenke, and 15 CSAN. Children with achondroplasia had significantly smaller sagittal diameter (mean 16.2 ± 2.4 mm) compared to other groups (control 31.7 ± 2.4 mm, p < 0.0001; Muenke 31.7 ± 3.5 mm, p < 0.0001; and CSAN 23.1 ± 3.4 mm, p < 0.0001) and transverse diameters (mean 14.3 ± 1.8 mm) compared with other groups (control 26.5 ± 3.2 mm, p < 0.0001; Muenke 24.1 ± 2.6 mm, p < 0.0001; CSAN 19.1 ± 2.6 mm, p < 0.0001). This translated into a surface area which was 3.4 times smaller in the achondroplasia group compared with the control group. The median grade of the AIOS fusion achondroplasia group was 3.0 (IQR 3.0-5.0), which was significantly higher compared with the control group (1.0, IQR 1.0-1.0, p < 0.0001), Muenke group (1.0, IQR 1.0-1.0, p < 0.0001), and CSAN (2.0, IQR 1.0-2.0, p < 0.0002). Median PIOS fusion grade was also highest in the achondroplasia group (5.0, IQR 4.0-5.0) compared with control (1.0, IQR 1.0-1.0, p < 0.0001), Muenke (2.5, IQR 1.3-3.0, p < 0.0001), and CSAN (4.0, IQR 4.0-4.0, p = 0.2). Distinct bony opisthion spurs projecting into the foramen magnum were seen in achondroplasia patients but not others, resulting in characteristic crescent and cloverleaf shapes. CONCLUSION: Patients with AFMS stages 3 and 4 have significantly reduced FM diameters, with surface area 3.4 times smaller than age-matched controls. This is associated with premature fusion of the AIOS and PIOS in comparison with controls and other FGFR3-related conditions. The presence of thickened opisthion bony spurs contributes to stenosis in achondroplasia. Understanding and quantifying bony changes at the FM of patients with achondroplasia will be important in the future quantitative evaluation of emerging medical therapies.

Midline-Sparing Interapophysealaminar Decompression Technique for Management of Lumbar Stenosis in Pediatric Achondroplasia.

INTRODUCTION: Achondroplasia is the most common form of short-limb dwarfism in humans, with an incidence of 1 in 25,000-40,000 live births. About one-third of achondroplasia patients will require operative intervention for lumbar spinal stenosis, generally presenting with progressive neurogenic claudication. The anatomy of the achondroplastic lumbar spine, with shortened pedicles, hypertrophic zygapophyseal joints, and thickened laminae frequently results in the development of multilevel interapophyseolaminar stenosis, while stenosis is usually absent at the mid-laminar levels secondary to pseudo-scalloping of the vertebral bodies. Treatment remains controversial, as disrupting the posterior tension band with complete laminectomies in the pediatric population puts patients at risk of developing post-laminectomy kyphosis. CASE PRESENTATION: A 15-year-old girl with achondroplasia presented to clinic with debilitating neurogenic claudication in the setting of multilevel lumbar interapophyseolaminar stenosis. We present a technical case report of her successful surgical treatment using a midline posterior tension band sparing modification to the interapophyseolaminar decompression technique proposed by Thomeer et al. [J Neurosurg. 2002;96(3 Suppl l):292-7]. CONCLUSION: We demonstrate that an adequate interapophyseolaminar decompression can be achieved through the performance of bilateral laminotomies, bilateral medial facetectomies, and undercutting of the ventral spinous process while preserving supraspinous and interspinous ligament attachments. Given the generally multilevel nature of lumbar stenosis and longer life expectancies of pediatric achondroplasia patients, decompressive surgical interventions must aspire to minimize disruption of spine biomechanics if fusion surgery is to be avoided.

Hemiepiphysiodesis for Lower Extremity Coronal Plane Angular Correction in the Distal Femur and Proximal Tibia in Children With Achondroplasia.

BACKGROUND: Achondroplasia is the most prevalent form of skeletal dysplasia, affecting more than 250,000 individuals. Lower extremity angular deformities, particularly genu varum, are common in children with achondroplasia, often resulting in pain and limitation of function. The authors aim to determine the utility of lower extremity growth modulation with hemiepiphysiodesis in children with achondroplasia for correction of coronal plane deformities about the knee. METHODS: The authors performed a retrospective chart review of a single center from 1/1/2000 to 12/31/2020 to identify pediatric patients with achondroplasia treated with hemiepiphysiodesis as their initial procedure at the distal femur and/or proximal tibia. Patients with adequate records and who had completed their treatment were included. Data collected included duration of treatment, complications, need for osteotomy, and radiographic measurements including initial and final mechanical axis deviation, knee mechanical axis zone, mechanical lateral distal femoral angle and medial proximal tibia angle. RESULTS: Ten patients with 17 limbs met our criteria. Nine patients (15 limbs) were treated for genu varum and 1 patient (2 limbs) was treated for genu valgum. Prior to treatment, the mechanical axis fell in zone 3 in 59% of limbs and zone 2 in 41%. Average correction in mechanical axis deviation was 26.1 mm. Average change in mechanical lateral distal femoral angle was 10.3 degrees per limb, and average change in medial proximal tibia angle was 7.1 degrees per limb. Average treatment duration was 909 days. At final follow up, 81% (14/17) of limbs had the mechanical axis in zone 1, with the remaining 18% (3/17) in zone 2. No patient/limb underwent subsequent distal femur or proximal tibia osteotomy for coronal plane alignment. CONCLUSIONS: Children with achondroplasia can successfully be treated with hemiepiphysiodesis to correct coronal plane deformities at the distal femur and proximal tibia. Using this technique, no patient in our series required an osteotomy for genu varum/valgum. LEVEL OF EVIDENCE: Therapeutic level IV, Case series.

Route of delivery does not impact postnatal surgical morbidity in pregnancies affected by fetal achondroplasia.

PURPOSE: Pregnancies affected by maternal or fetal achondroplasia present unique challenges. The optimal route of delivery in fetuses with achondroplasia has not been established. Our objective was to determine whether the route of delivery affects postnatal achondroplasia-related surgical burden. METHODS: We conducted a secondary analysis of Achondroplasia Natural History Study (CLARITY), which is a multicenter natural history cohort study of patients with achondroplasia. Achondroplasia-related surgical morbidity, which we defined as the need for one or more postnatal achondroplasia-related surgeries, was assessed in relation to the route of delivery and whether the mother also had achondroplasia. Rate of each individual surgery type (otolaryngology, brain, foramen magnum, spine, and extremity) was also assessed in relation to the route of delivery. RESULTS: Eight hundred fifty-seven patients with achondroplasia with known route of delivery and known maternal stature were included. Three hundred sixty (42%) patients were delivered vaginally, and 497 (58%) patients were delivered by a cesarean delivery. There was no difference in the odds of requiring any postnatal achondroplasia-related surgery in those with achondroplasia who were delivered vaginally compared with those delivered by cesarean birth (odds ratio 0.95, 95% CI = 0.68-1.34, P = .80). No difference was present in the odds of requiring any postnatal achondroplasia-related surgery when route of delivery was compared for fetuses born to 761 average stature mothers (odds ratio 1.05, 95% CI = 0.74-1.51, P = .78). There was also no difference in the odds of requiring each of the individual achondroplasia-related surgeries by route of delivery, including cervicomedullary decompression. CONCLUSION: Our study suggests that it is reasonable for average stature patients carrying a fetus with achondroplasia to undergo a trial of labor in the absence of routine obstetric contraindications.

[Preliminary study of Ilizarov technique in treatment of lower limb deformity caused by achondroplasia].

Objective: To investigate the surgical method and preliminary effectiveness of Ilizarov technique in the treatment of lower limb deformity caused by achondroplasia. Methods: The clinical data of 38 patients with lower limb deformity caused by achondroplasia treated by Ilizarov technique between February 2014 and September 2021 were retrospectively analyzed. There were 18 males and 20 females, the age ranged from 7 to 34 years, with an average of 14.8 years. All patients presented with bilateral knee varus deformity. The preoperative varus angles was (15.2±4.2)°, and knee society score (KSS) was 61.8±7.2. Nine of these patients underwent tibia and fibula osteotomy, 29 cases underwent tibia and fibula osteotomy and bone lengthening at the same time. Full-length bearing position X-ray films of bilateral lower limbs were taken to measure the bilateral varus angles, analyze the healing index, and record the occurrence of complications. KSS score was used to evaluate the improvement of knee joint function before and after operation. Results: All 38 cases were followed up 9-65 months, with an average of 26.3 months. Needle tract infection occurred in 4 cases and needle tract loosening occurred in 2 cases after operation, which were improved after symptomatic treatment such as dressing change, Kirschner wire change, and oral antibiotics, and no neurovascular injury occurred in all patients. The external fixator was worn for 3-11 months after operation, with an average of 7.6 months, and the healing index was 43-59 d/cm, with an average of 50.3 d/cm. At last follow-up, the leg was 3-10 cm longer, with an average of 5.5 cm. The varus angles was (1.5±0.2)° and the KSS score was 93.7±2.6, which significantly improved when compared with those before operation ( P<0.05). Conclusion: Ilizarov technique is a safe and effective method for the treatment of short limb with genu varus deformity caused by achondroplasia, which can improve the quality of life of patients.

Assessment of body fat mass, anthropometric measurement and cardiometabolic risk in children and adolescents with achondroplasia and hypochondroplasia.

Achondroplasia is a rare skeletal dysplasia characterized by rhizomelic short stature, whose prevalence is about 1 per 25,000 births. For some patients with achondroplasia, excess body weight is one of the major concerns due to an impaired linear growth. Epidemiological studies revealed a premature onset of cardiovascular or cerebrovascular events in achondroplasia. An association between obesity and cardiometabolic risk factors related to cardiovascular events remains unknown in patients with achondroplasia/hypochondroplasia. This cross-sectional study investigated anthropometric measurements, body compositions and cardiometabolic risk factors in pediatric patients with achondroplasia/hypochondroplasia. Thirty-two patients with achondroplasia and ten with hypochondroplasia aged between 1.9 and 18.7 years were enrolled in this study. Half of the participants presented at least one cardiometabolic abnormality. Elevated systolic blood pressure was the most common abnormality. None of the participants developed metabolic syndrome or type 2 diabetes mellitus. Body mass index-standard deviation score and hip/height ratio were strongly correlated with percent body fat assessed by dual energy X-ray absorptiometry although no significant association was found between anthropometric measurements or body fat mass and any cardiometabolic risk factors. No significant difference in body fat mass, as well as body mass index-standard deviation score and hip/height, was found between cardiometabolically normal group and cardiometabolically abnormal groups. These results suggest that not only weight gain and hip/height changes should be monitored but also individual cardiometabolic risk factors should be evaluated to avoid cardiometabolic events in the healthcare management of pediatric patients with achondroplasia/hypochondroplasia.